A liquid crystal display (LCD) device includes a liquid crystal (LC) panel, and a backlight unit that provides a light source for the LC panel. The LC panel includes a plurality of thin film transistors (TFTs), scan lines, and data lines. The data lines and the scan lines crisscross with each other. Each of the scan lines controls gate electrodes of one row of TFTs, each of the data lines is connected with source electrodes of one column of TFTs, and a drain electrode of each of the TFTs is connected with one pixel electrode to form a pixel capacitor. The pixel capacitor includes the pixel electrode and a common electrode, which are opposite to each other. The pixel electrode is connected with the drain electrode of each of the TFTs, and a constant voltage signal is generally sent to the common electrode. LC molecules are filled between the pixel electrode and the common electrode, and a voltage difference between the pixel electrode and the common electrode may be controlled by adjusting an output voltage of the data line, thus deflection angle of the LC molecules can be adjusted, which controls luminous flux.
In order to avoid irreversible damage of the LC molecules by a constant electric field, a polarity inversion method is used for driving the LC panel, namely voltage inversion of the data lines is controlled, and the voltage difference between the pixel electrode and the common electrode is constant. Even though direction of the LC molecules changes with an inversion of the electric field, deflection angle of the LC molecules keeps constant, thus, display effect of the LC panel is not affected. The polarity inversion method includes a row inversion, a column inversion, and a dot inversion. Display effect of the LC panel is best when the dot inversion is used for driving the LC panel. However, LC pixel voltage of the LC panel driven by the dot inversion method continually changes between a positive pixel voltage and a negative pixel voltage, thus, power loss of the dot inversion method is great. Additionally, the data lines and the pixel capacitors have great capacitance, thus, power loss of the data driving circuit is mainly in an entire driving circuit. Therefore, how to reduce dynamic power loss of the data driving circuit is an important concern.